Almost Gorenstein rings are a class of Cohen-Macaulay rings, introduced by Barucci and Fröberg in 1997 (cf. [1]}), which are close to Gorenstein rings. This class of rings was originally defined in the context of analytically unramified rings of dimension one, however this definition has been later generalized in the context of one-dimensional rings (cf. [2]}), and then to the higher dimension case (cf. [3]}).
